The NHS could claim back over half a billion pounds from Pfizer - following a long-running controversy that saw GPs having to switch patients between generic and branded pregabalin - after the Supreme Court ruled that the drug company’s patent for Lyrica (pregabalin) is invalid.

The judgement, handed down this morning, dismissed Pfizer’s final attempt to uphold its patent, and accused the company of trying to hold a ‘monopoly’ with ‘insufficient’ evidence.

Speaking at the Supreme Court today, Lord Sumption read the judgement, and explained that the patent was deemed invalid due to a lack of evidence for the conditions it covered - central and peripheral neuropathic pain.

He said: ‘Although the patent specification showed sufficiently why pregabalin could be expected to work with peripheral neuropathic pain, it didn’t show any scientific reason why it would be expected to work for central neuropathic pain. Since the patent covered both, the disclosure was therefore insufficient.'

‘The Supreme Court unanimously agrees that the patent claimed a monopoly on all neuropathic pain,' he continued.

Lord Sumption concluded: ‘Since Warner-Lambert (Pfizer) do not challenge the finding that the specification made insufficient disclosure as regard to central neuropathic pain, it follows that the patent was invalid for sufficiency of disclosure. The specification was insufficient. On that ground we dismiss Warner-Lambert’s (Pfizer's) appeal.’

Earlier this year, researchers calculated the amount that the NHS paid for pregabalin, and compared it with the amount they would have paid if pregabalin had been generically available from October 2015 - when GPs were forced to change patients from generic pregabalin to branded - to July 2017 - when the second patent ran out. This resulted in a difference of £502m.

The study, published by bioRXiv and led by University of Oxford in collaboration with an intellectual property law firm, aimed to highlight the variation in the prescribing rates of branded pregabalin.

A spokesperson for the Department of Health and Social Care said: 'We will carefully consider the judgment and its impact, including the possibility to seek damages.'

Meanwhile, a Pfizer spokesperson said: ‘As situations such as these are expected to become more common, it’s important for patients that pharmaceutical companies are able to protect patents, including second medical use patents.

‘This is why Pfizer is disappointed with the decision issued by the Supreme Court in London regarding the second medical use patent covering Lyrica (pregabalin) for pain.’

The pregabalin dispute

The pharma giant’s main patent for Lyrica – indicated for seizure disorders - in the UK expired in 2013, but at that time it still held a ‘second medical use’ patent for the drug, when prescribed for neuropathic pain.

After the initial patent ran out generic versions of pregabalin came onto the market, meaning that GPs could prescribe a generic version instead of Lyrica for neuropathic pain, despite the second patent.